unresolved inclusion: <math.h>

Dear All,

I use YAGARTO Tools  and Eclipse to test the model "SAM7X256Test" 
download from http://www.yagarto.de/howto/examples/index.html. In order 
to use some functions such as sin(), pow(), I include math.h in the 
source code.

There is no error during the building. But in Eclipse, there is a red 
waveline under "#include <math.h>". When I move the cursor on the line, 
it shows "unresolved inclusion: <math.h>".

could you tell me what is the problem?

Thanks a lot!

hansflying